Mechanisms of Direct and TiO2-Photocatalysed UV-Photodegradation of Environmentally Relevant N-Phenyl Derivatives
|Moisés Canle L 1, Isabel Fernández , Arturo Santaballa 1|
1. Universidade da Coruña (UDC), Alejandro de la Sota, Coruña 15008, Spain
N-phenyl derivatives are relevant in different fields, and eventually dispersed in the environment. Thus, N-phenyl ureas, a group of herbicides believed to inhibit photosynthesis, are highly persistent, with half-life times of several months. N-phenyl carbamates are widely used insecticides (inhibiting acetylcholinesterase) and herbicides (inhibiting e--transfer in thylakoids, uncoupling photo- and oxidative phosphorylations). An additional example may be N-Phenyl-Glycine, commonly used in the synthesis of textile dyes. The available mechanistic studies on the direct and photocatalysed photodegradation of these compounds are conflicting and scarce . We decided to carry out comparative mechanistic studies on their direct and TiO2-photocatalysed UV aqueous photodegradation .
We report on both the photophysics and photochemistry of different N-phenyl derivatives, including photoproducts, rate studies, quantum yields, ionization potentials, reduction potentials and pKa's of short-lived intermediates, etc. These data help us elucidate the mechanisms of the different processes under study, both for the direct and for the TiO2-photocatalysed UV photodegradation.
Acknowledgement: the Xunta de Galicia (Spain) financed this research through project PGIDIT05TAM10301PR.
 H. D. Burrows, L, M. Canle, J. A. Santaballa, S. Steenken, J. Photochem. Photobiol. B: Biology 2002, 67(2), 71.
 a) M. L. Canle, M. I. Fernandez, S. Rodriguez, J. A. Santaballa, S. Steenken, E. Vulliet, Chem. Phys. Chem. 2005, 6, 2064. b) L. M. Canle, J. A. Santaballa, E. Vulliet, J. Photochem. Photobiol. A: Chemistry 2005, 175, 192. c) L. M. Canle, J. A. Santaballa, S. Steenken, Chem. Eur. J. 1999, 5, 1192.
Presentation: oral at 18th Conference on Physical Organic Chemistry, Symposium 2, by Moisés Canle L
See On-line Journal of 18th Conference on Physical Organic Chemistry
Submitted: 2006-06-01 23:04 Revised: 2009-06-07 00:44
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